Corning® Filtration Guide

Corning® Filtration Guide Innovative Products for Filtration and Ultrafiltration

Contents Filtration Selecting the Best Filter for Your Application............................................................................... 1 Improving Filter Performance . ........................................................................................................ 5 Safety Precautions............................................................................................................................... 7 Bibliography.......................................................................................................................................... 7 Ordering Information................................................................................................................... 8-11

Ultrafiltration................................................................................................................................... 12 Introduction......................................................................................................................................... 12 Choosing the Right Concentrator Doesn’t Have to Be Complicated.................................... 12 Choosing the Best Molecular Weight Cut-off Membrane....................................................... 14 Helpful Hints............................................................................................................................... 14-15 Chemical Compatibility............................................................................................................ 15-16 Ordering Information................................................................................................................ 16-17

F i l t ra t io n Selecting the Best Filter for Your Application

Choosing a filter does not have to be complicated – Corning has simplified the process. Just follow these four easy steps: Step 1: Match your application with the best pore size. Step 2: Select the best membrane and housing material for your application. Step 3: Select the correct membrane area to optimize flow rate and throughput. Step 4: Choose the best filter design for your application.

Step 1: Match your application with the best pore size. The pore size is usually determined by your application or objective. Mycoplasma removal can be performed using a 0.1 µm pore filter. Routine ­labora­tory sterilization of most media, buffers, biological fluids and gases is usually done with 0.2 or 0.22 µm pore filter membranes. Clarification and prefiltration of ­solutions and solvents is best accomplished with 0.45 µm or larger filter membranes. Prefiltration to improve filter performance can also be accomplished by the use of glass fiber prefilters that can be purchased separately. Use Table 1 to match your applications with a recommended membrane and pore size. Table 1. Selecting the Pore Size Application

Pore Size (µm)

Mycoplasma Removal

Membrane Availability

0.1

PES*

Sterilization and Ultracleaning of Aqueous Solutions

0.20 to 0.22

All membranes except PTFE

Ultracleaning of Solvents (HPLC)

0.20 to 0.22

RC,* nylon and PTFE

Clarification of Aqueous Solutions

0.45

All membranes except PTFE

Clarification of Solvents (HPLC)

0.45

RC, nylon and PTFE

Coarse Particle Removal

0.8

SFCA,* glass fiber prefilters

*RC = regenerated cellulose; SFCA = surfactant-free cellulose acetate; PES = polyethersulfone, PTFE = polytetrafluorethylene.

Step 2: Select the best membrane and housing material for your application. Corning Filter Membranes Your filter unit must be fully compatible with the chemical characteristics of your s­ ample. Some filter membranes contain non-toxic wetting agents that may interfere with some applications. Other membranes may bind proteins or other macromolecules leading to premature filter clogging or loss of valuable samples. Therefore, it is very important to understand their char­ acteristics and the potential effects filter membranes can have on the solutions they contact. The information from Tables 2 and 3 will help you choose the best Corning® membranes for your applications. Table 2. Characteristics of Corning Filter Membranes

Cellulose Cellulose Nitrate Acetate Nylon

Wetting Yes Yes Agents

Polyether- Regenerated sulfone cellulose

No, naturally No Yes hydrophilic

PTFE*

Does not wet

Protein Very high Very low Binding

Low to moderate

Very low

Low

NA

DNA Binding

Very high

Very low

Low

NA

Very high

Very high

High

Very low

Chemical Low Low Resistance

Moderate Low to high

*PTFE = polytetrafluorethylene.

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Cellulose acetate (CA) membranes have a very low binding affinity for most macromolecules and are especially recommended for applications requiring low protein binding, such as filtering culture media containing sera. However, both cellulose acetate and cellulose nitrate membranes are naturally hydrophobic and have small amounts (less than 1%) of non-toxic wetting agents added during manufacture to ensure proper wetting of the membrane. If desired, these agents can be easily removed prior to use by filtering a small amount of warm purified water through the membrane or filter unit. Surfactant-free cellulose acetate membranes with very low levels of extractables are available on some Corning® syringe filters. Cellulose nitrate (CN) membranes are recommended for filtering solutions where protein binding is not a concern. They are recommended for use in general laboratory applications such as buffer filtration. Corning’s cellulose nitrate membranes are Triton® X-100-free and noncytotoxic. Nylon membranes are naturally hydrophilic and are recommended for applications requiring very low extractables since they do not contain any wetting agents, detergents or surfactants. Their greater chemical resistance makes them better for filtering more aggressive solutions, such as alcohols and DMSO. However, like cellulose nitrate membranes, they may bind greater amounts of proteins and other macromolecules than do the cellulose acetate or PES membranes. They are recommended for filtering protein-free culture media. Polyethersulfone (PES) membranes are highly recommended for filtering cell culture media. PES has both very low protein binding and extractables. PES also demonstrates faster flow rates than cellulosic or nylon membranes. Regenerated cellulose (RC) membranes are hydrophilic and have very good chemical resistance to solvents, including DMSO. They are used to ultraclean and de-gas solvents and mobile phases used in HPLC applications. Polytetrafluorethylene (PTFE) membranes are naturally and permanently hydro­­phobic. They are ideal for filtering gases, including humidified air. The extreme chemical resistance of PTFE membranes makes them very useful for ­filtering solvents or other aggressive chemicals for which other membranes are unsuitable. Because of their hydro­phobicity, PTFE membranes must be prewetted with a solvent, such as ethanol, before a­ queous solutions can be filtered. Glass fiber filters are used as a depth filter for prefiltration of solutions. They have very high particle loading capacity and are ideal for prefiltering dirty solutions and difficult-to-filter biological fluids, such as sera. Corning Filter Housing Materials The filter housing materials, as well as the filter membrane must be compatible with the solutions being filters. Polystyrene (PS) is used in the filter funnels and storage bottles for all of the Corning ­plastic vacuum filters. This plastic polymer should only be used in filtering and storing nonaggressive aqueous solutions and biological fluids. Refer to Table 3 for more chemical compatibility information. Acrylic copolymer (AC) and Polyvinyl chloride (PVC) are used in some of the Corning syringe filter housings. These plastics should only be used in filtering nonaggressive aqueous solutions and biological fluids. Refer to Table 3 for more chemical compatibility information. Polypropylene (PP) is used in the Spin-X® centrifuge filters and some of the syringe and disc filter housings. This plastic polymer has very good resistance to many solvents, refer to Table 3 for more chemical compatibility information.

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Chemical Compatibility The mechanical strength, color, appearance, and dimensional stability of Corning® filters are affected to varying degrees by the chemicals with which they come into contact. Specific operating conditions, especially temperature and length of exposure, will also affect their chemical resistance. Table 3 provides a general guideline for the chemical resistance of Corning filter membranes and housings. Table 3. Chemical Resistance Guide for Corning Filters*

Filter Membranes Chemical Class

Weak Acids

CN

CA

NY

PES

Housing Materials RC

PTFE

PS

PP

AC

PYR

2 2 2 3 1 1 1 1 2 1

Strong Acids

3 2 3 3 3 1 2 1 3 2

Alcohols

3 1 1 1 1 1 2 1 3 1

Aldehydes

2 3 2 3 2 1 3 1 3 1

Aliphatic Amines 3 3 1 1 1 1 3 1 3 1 Aromatic Amines 3 3 2 3 1 1 3 1 3 1 Bases

3 3 2 3 2 1 1 1 2 2

Esters

3 3 1 3 1 1 3 2 2 1

Hydrocarbons 2 2 2 3 1 1 3 2 2 1 Ketones 1

3 3 2 3 1 1 3 2 3

Key: 1 = Recommended; 2 = May be suitable for some applications, a trial run is recommended; 3 = Not recommended; CN = cellulose nitrate; CA = cellulose acetate; NY = nylon; PYR = Pyrex® Glass; PES = polyethersulfone; RC = regenerated cellulose; PS = polystyrene; PTFE = polytetrafluorethylene ; PP = polypropylene; PVC = polyvinylchlorides; AC = acrylic copolymer. * This information has been developed from a combination of laboratory tests, technical publications, or material suppliers. It is believed to be reliable. Due to conditions outside of Corning’s control, such as variability in temperatures, concentrations, d ­ uration of exposure and storage conditions, no warranty is given or is to be implied with respect to this information.

Step 3: Select the correct membrane area to optimize flow rate and throughput. The third step is selecting a filter that will have enough volume capacity or throughput to process your entire sample quickly and efficiently. This is primarily determined by the effective surface area of the membrane. Table 4 shows the relationship between filter size, effective filtration surface area and expected throughput volumes. The lower values are typical of viscous or particle-laden solutions; the higher values are typical of buffers or serum-free medium. Table 4. Typical Expected Throughput Volumes Filter Diameter/Dimension and Description

Effective Filter Area (cm2)

Expected Throughput (mL)*

4 mm syringe/disc

0.07

0.05-3

15 mm syringe/disc

1.7

3-15

25 mm syringe/disc

4.8

10-50

26 mm syringe/disc

5.3

10-50

28 mm syringe/disc

6.2

10-50

50 mm disc

19.6

100-500

42 mm vacuum system/square

13.6

100-500

49.5 mm vacuum system/square

19.6

200-750

63 mm vacuum system/square

33.2

300-1500

79 mm vacuum system/square

54.5

500-3000

*These values assume an aqueous solution and a 0.2 micron membrane. Solutions containing sera or other proteinaceous materials will be at the lower end of the range. Use of prefilters may extend the throughput 50 to 100% above the values shown.

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Step 4: Choose the best filter design for your application. Corning offers three basic filter types: positive pressure-driven syringe and disc filters, S ­ pin-X® centrifuge tube filters driven by centrifugation, and vacuum-driven filters. The vacuum-driven filters offer several different designs and styles in disposable plastic products. Syringe/Disc Filters The smaller conventional Corning® syringe disc-type filters (4, 15, and 25, 26 and 28 mm diameter) are used with syringes which serves as both the fluid reservoir and the pressure source. They are 100% integrity tested. The HPLC-certified non-sterile syringe filters are available with nylon, regenerated cellulose or polytetrafluorethylene (PTFE) membranes in polypropylene housing for extra chemical resistance. The sterile tissue culture tested syringe filters are available in PES, regenerated cellulose (ideal for use with DMSOcontaining solutions), or surfactant-free cellulose acetate membranes in either polypropylene or acrylic copolymer housings.

Corning Syringe Filters

The larger 50mm diameter disc filter has a PTFE membrane and poly­propylene housing with hose barb connectors. This product is ideal for filtering aggressive solvents or gases and applications requiring sterile venting of gases. Because they have a hydrophobic (will not pass aqueous solutions) membrane, they are also ideal for protecting vacuum lines and pumps. Corning Disposable Plastic Vacuum Filters These sterile filters are available in three styles: complete filter/storage systems, bottle top filters and centrifuge tube top filters. Corning filters feature printed funnels that identify membrane type and product number for easy product identification. Angled hose connectors simplify vacuum line attachment. Four membranes are available to meet all of your filtration needs: cellulose acetate, cellulose nitrate, nylon, or polyethersulfone. Corning filter/storage systems consist of a polystyrene filter funnel joined by an adapter ring to a removable polystyrene storage bottle with a separate sterile polyethylene cap. Receiver bottles feature easy grip sides for improved handling. Additional Corning ­poly­styrene receiver/storage bottles can be ordered separately to increase throughput.

Corning Filter/Storage Systems

Corning bottle top filters have the same polystyrene filter funnel designs and capacities as the filter systems, but the adapter ring is designed for threading onto a glass bottle supplied by the user. Select either the 33 mm thread design for standard narrow glass mouth media bottles or the 45 mm design for PYREX® Media Bottles or PyrexPlus® Media bottles. See Safety Precautions for ­recommendations on using these products with glass bottles (page 7). 150 mL centrifuge tube top filters feature a 150 mL polystyrene filter funnel with a 50 mm diameter cellulose acetate membrane attached to a 50 mL polypropylene centrifuge tube to minimize unnecessary transfers by filtering directly into centrifuge tube.

Corning Spin-X Centrifuge Tube Filters

4

Corning Spin-X Centrifuge Tube Filters Spin-X centrifuge tube filters consist of a membrane-containing (either cellulose acetate or nylon) filter unit within a polypropylene centrifuge tube. They filter small sample volumes by centrifugation for bacteria removal, particle removal, HPLC sample preparation, removal of cells from media and purification of DNA from agarose and polyacrylamide gels. (See Corning Technical Bulletin: Spin-X ­purification of DNA from agarose gels, page 6.)

Improving Filter Performance Getting the best performance from your filtration products requires two very i­mportant steps: selecting the right products for the job, and then using these ­products effectively. The first part of this brochure covered the steps required to select the right filter for your applications; this section will help you optimize the filtration pro­cess by keying on the two most important areas – maximizing filter flow rate and throughput or capacity. The flow rate and throughput of filters are dependent on many variables. Some variables, such as temperature, pressure, and especially, the characteristics of the sample, require ­special attention.

Effect of Pore Size The pore size of filter membranes is usually dictated by the requirements of the filter application rather than the desired flow rate. Larger pore membranes usually have both faster flow rates and greater capacity before pore clogging slows the flow. Figure 2 indicates the effect of pore size on filter performance. As expected, the initial flow rate (steep part of the curve) of the .45 µm filter was approximately twice that of the .22 µm filter, although its capa­city or throughput prior to clogging (the area at the plateau) was only about 20% greater. Figure 2. Effect of Size on Performance

Volume Filtered (ml)

600

.45 µm pores

400

Maximum flow rate

Test Conditions: Medium containing 10% fetal bovine serum was filtered using cellulose acetate membranes at 23°C and 600 mm Hg vacuum.

Approaching total capacity

.22 µm pores

200

0 0

60

120

180

240

300

time Required (seconds)

Table 5. Corning Filter Designs Design Sterile

Filter Diameters/ Dimensions (mm)

Available Membrane Materials

Pore Sizes (µm)

Special Features

Syringe Filters Some

4, 15, 25, 26 and 28

RC, PES, SFCA, NY and PTFE

0.2. 0.45, and 0.8

Ideal for small volume pressure filtration

50

PTFE

Disc Filters

Yes

0.2

Ideal for filtering solvents and gases

Vacuum Filter Yes 42, 49.5, PES, CA, CN Systems* 63, 79 and Nylon

0.2 (NY only), Easy grip bottles for storing filtrate 0.22 (PES, CN), and 0.45 (CA only)

Bottle Top Yes 42, 63, 79 PES, CA, CN Vacuum Filters* and Nylon

0.2 (NY only), 0.22 (PES, CA, CN), and 0.45 (CA only)

Two neck widths to fit most glass bottles

Tube Top Yes 42 CA 0.22 and 0.45 Vacuum Filters*

Minimizes unnecessary transfers by filtering into a 50 mL centrifuge tube

Some 7.7 CA and Nylon 0.22 and 0.45 Spin-X® Centrifuge Filters

Ideal for purifying DNA from agarose gels

Key: CN = cellulose nitrate; CA = cellulose acetate; PES = polyethersulfone; RC = regenerated cellulose; PTFE = polytetrafluorethylene. *Vacuum Filter Systems, Bottle Top Vacuum Filters and Tube Top Vacuum Filters have a square membrane.

5

Effect of Membrane Area The easiest and most practical way to increase filter flow rate is to increase the effective ­surface area of the filter membrane. Corning offers both syringe and v­ acuum filter units with a choice of membrane diameters that give a wide range of flow rates and throughputs (See Table 4). Effect of Fluid Temperature For most applications, filtering solutions at room temperature is fine. Usually increasing the temperature of a solution will increase the flow rate. For example, increasing the temperature of cell culture medium from 4°C to 37°C resulted in a doubling of the flow rate. This is most likely due to a decrease in the viscosity of the medium. In some cases, however, filtration at lower temperatures may increase the overall throughput, especially with protein and lipidcontaining solutions such as serum. Effect of Pressure Differential For vacuum-driven filtration, a pressure differential (vacuum) of 400 mm Hg (7.73 psig) is recommended. Increasing the pressure differential further will slightly increase the flow rate, but it may also result in excess foaming as the gases in the filtrate come out of solution as bubbles. This is especially a problem with filtering bicarbonate-buffered cell culture media. The ­dissolved carbon dioxide in the medium will evolve quickly at higher-pressure differ­ entials leading to a rise in pH and excessive foaming if serum proteins are present.

Spin-X® tube Purification of DNA from Agarose Gels Introduction Purification of DNA from an agarose gel with the Spin-X tube is quick and efficient, unlike the electro­elution, dialysis, and “freeze-squeeze” methods. The Spin-X method consists of two simple steps: excision of the band from the gel and centrifugation in the Spin-X tube. Yields range from 30 to 80%. Protocol* 1. Electrophorese DNA in an agarose gel containing ethidium bromide. 2. After electrophoresis, illuminate the gel under long wavelength UV light, then, using a sharp instrument, carefully excise the band of interest (30-15,000 bp). 3. Place the gel slice into the filter cup of the Spin-X tube (Cat. No’s. 8160, 8161, 8162, 8163) and mix with 100 to 200 µL of distilled water or Tris-EDTA. 4. Spin the tube at about 13,000 x g for 5 to 20 minutes at room temperature. 5. Collect the DNA from the microcentrifuge tube; the agarose gel will be retained on the Spin-X membrane. If needed, ethanol precipitate the DNA to remove any EDTA present. Note: DNA yield may increase with the incorporation of one or all of the following steps: 1. Macerate the gel slice prior to placement in the Spin-X tube. 2. Prior to centrifugation in step #4, freeze the gel slice at -70°C in a separate tube, then allow to thaw. 3. After the initial centrifugation, add an additional 200 µL of buffer to the Spin-X tube and ­centrifuge again. 4. Spin for a longer period of time. *Schwarz, Herbert and Whitton, J. Lindsay, 1992. A Rapid, Inexpensive Method for Eluting DNA from Agarose or Acrylamide Gel Slices Without Using Toxic or Chaotropic Materials. Vol. 13, No. 2, Biotechniques.

6

Effect of Prefiltration A simple way to improve filter performance is to pretreat your solution. High speed centrifugation will remove most suspended particles and reduce filter clogging, extending both flow rate and throughput (Corning® 250 and 500 mL centrifuge ­bottles are ideal for centrifuging larger liquid volumes). Prefiltration through a glass fiber pad or depth filter will also reduce particle load and premature membrane clogging. The use of a glass fiber prefilter has been demonstrated to more than double the throughput when filtering calf serum. These glass fiber prefilters are available for all Corning vacuum filter systems and bottle top filters. For particularly difficult to filter solutions, it may be helpful to first prefilter the solution through a larger pore membrane filter.

Safety Precautions Corning filter units are intended for use by persons knowledgeable in safe laboratory practices. Safety is one of the most critical concerns of any lab. Because of variations in conditions, Corning cannot guarantee any glassware or plasticware against breakage under vacuum or pressure. Failure can result from surface damage, improper pressure or temperature, or use with incompatible chemicals. Adequate precautions should always be taken to protect personnel doing such work. To help improve lab safety, Corning has compiled these commonsense suggestions ­concerning the safe use of filtration products: w Use of vacuum-driven filters on glass or plastic bottles may cause personal injury if they

implode during use. Eye protection is strongly recommended whenever glass or plastic vessels are used under partial vacuum negative pressure to guard against these injuries. Only bottles specifically designed for these applications should be used. w Never use the 45 mm threaded bottle top filters on Pyrex® or PyrexPlus® Media Bottles

larger than 2 liter capacity or that are square. Use of bottle top filters with PyrexPlus Media Bottles (with plastic safety coatings) is highly r­ ecommended for vacuum filtration. w Never use the 33 mm threaded bottle top filters on standard glass media bottles that are larger

than 500 mL or on bottles that are not cylindrical. w Never use plastic roller bottles as substitute receiver bottles during vacuum filtration. w Do not use a bottle for vacuum applications if it is not designed to withstand a vacuum;

if the bottle is scratched, chipped or cracked; if the bottle is clamped in such a way as to induce stress; or if the bottle is being hand held. w Care must be taken when using syringe filters with small syringes (5 mL or less) as the pres-

sures generated may exceed the 75 psi limit, causing a possible membrane or housing failure. Loss of valuable contents and personal injury may result. If clogging causes slower flow rates, we recommend that you replace fi ­ lters rather than increase the pressure.

Bibliography Brock, TS. Membrane Filtration: A User’s Guide and Reference Manual. Science Tech, Inc. Madison, WI, 1983. Lukaszewicz, RC and Fisher, R. Mechanisms of Membrane Filtration for Particulate and Microbial Retention in Critical Applications. Pharmaceutical Technology, Vol. 5: June 1981. Walsh, RL and Coles, ME. Binding of IgG and other Proteins to Microfilters. Clin. Chem. 26(3):496-498, 1981.

7

Ordering Information Syringe Filters w A variety of membranes are available to meet your needs: polyethersulfone (PES) –

low protein binding and faster flow rates; surfactant-free cellulose acetate (SFCA) – lowest protein binding; polytetrafluorethylene (PTFE) – chemical resistance; regenerated ­cellulose (RC) – best choice for DMSO compatibility; nylon (NY) – hydrophilic, surfactant-free and ­lowest extractable. w 100% integrity tested, certified nonpyrogenic and noncytotoxic, manufactured in a ­ ccordance

with ISO 9002 standards

Syringe Filters Ordering Information Pore Diameter Size Cat. No. (mm) (µm)

Membrane Material

Housing Material Sterile

Inlet/ Outlet Packaging

Qty/ Cs

431212 4 0.2

RC

PP Yes LL/LS Ind 50

431215 15 0.2

RC

PP Yes LL/LS Ind 50

431218 28 0.2 SFCA-PF AC Yes LL/LS Ind 50 431219 28 0.2

SFCA

AC Yes LL/LS Ind 50

431220 28 0.45 SFCA

AC Yes LL/LS Ind 50

431221 28 0.8

SFCA

AC Yes LL/LS Ind 50

431222 25 0.2

RC

PP Yes LL/LS Ind 50

431224 25 0.2

NY

PP Yes LL/LS Ind 50

431225 25 0.45

NY

431227* 50 0.2

PTFE

PP Yes LL/LS Ind 50

431229 28 0.2

PES

PP

Yes HB/HB Ind 12

AC Yes LL/LS Ind 50

431231 25 0.45 PTFE

PP No LL/LS Bulk 50

PP = polypropylene, AC = acrylic copolymer, LL = Luer lock/female, LS = Luer slip/male, HB = hose barb, NY = nylon, PES = polyethersulfone, PTFE = polytetrafluorethylene, RC = regenerated cellulose, SFCA = surfactant-free cellulose acetate, SFCA-PF = surfactant-free cellulose acetate with prefilter. *Recommended as in-line air filter.

Spin-X® Centrifuge Tube Filters w Costar® Spin-X centrifuge tube filters consist of a membrane-containing filter unit within a

microcentrifuge tube. w Uses:

- Removing bacteria, cells and particles from liquids - HPLC sample preparation - DNA removal from agarose or acrylamide gels. Maximum RCF (Relative Centrifugal Force [x g]) is 16,000.

Spin-X Centrifuge Tube Filters Ordering Information Cat. No.

Membrane

Working

Material

Volume (µL)

(µm)

Sterile

Tube Size (mL)

Qty/Cs

8160 CA

500

0.22 Yes 2.0 96

8161 CA

500

0.22 No 2.0 100

8162 CA

500

0.45 Yes 2.0 96

8163

500

0.45 ­No

CA

2.0

100

8169 NY 500

0.22 No 2.0 200

8170 NY 500

0.45 No 2.0 200

CA = cellulose acetate, NY = nylon.

8

Pore Size

150 mL Tube Top Vacuum Filters w 42 mm square membrane w Minimizes unnecessary transfers by filtering directly into a 50 mL centrifuge tube w Includes two centrifuge tube stands with each case w Each polypropylene centrifuge tube is supplied with an individually wrapped cap for s­ torage w Individually packaged, sterile, certified nonpyrogenic

150 mL Tube Top Vacuum Filters Ordering Information Cat. No. Membrane

Funnel Size/ Tube Size (mL)

Pore Size (µm)

Qty/Cs

430314 CA

150/50

0.45

12

430320 CA

150/50

0.22

12

CA = cellulose acetate.

Vacuum Filter Systems w Four sizes: 150 mL, 250 mL, 500 mL and 1L w Filters feature printing on the funnel for easy product identification. w Angled hose connector simplifies vacuum line attachment. w Receiver bottles feature easy grip sides for improved handling. w Individually packaged, sterile, certified nonpyrogenic w Caps for receiver bottles are sterile and individually packaged. w Extra plastic storage bottles are available, see page 11. w Prefilters not included

Vacuum Filter Systems Ordering Information Cat. No.

Membrane

Funnel/Bottle Volume (mL)

Pore Size (µm)

Qty/Cs

150 mL Capacity, 42 mm Square Membrane 431153 PES 431154 CA 431155 CA

150/150 150/150 150/150

0.22 12 0.22 12 0.45 12

250 mL Capacity, 49.5 mm Square Membrane 430756 CN 430767 CA 430768 CA 430771 NY 431096 PES

250/250 250/250 250/250 250/250 250/250

0.22 0.22 0.45 0.2 0.22

12 12 12 12 12

500 mL Capacity, 63 mm Square Membrane 430758 CN 430769 CA 430770 CA 430773 NY 431097 PES 431475 PES

500/500 500/500 500/500 500/500 500/500 500/500

0.22 0.22 0.45 0.2 0.22 0.1

12 12 12 12 12 12

0.22 0.2 0.45 0.22 0.22 0.22 0.45 0.1

12 12 12 12 12 12 12 12

1,000 mL Capacity, 79 mm Square Membrane 430186 CN 1,000/1,000 430515 NY 1,000/1,000 430516 CA 1,000/1,000 430517 CA 1,000/1,000 431098 PES 1,000/1,000 431205* CA 500/1,000 431206* CA 500/1,000 431474 PES 1,000/1,000 *500 mL funnel with 63 mm membrane. PES = polyethersulfone, CA = cellulose acetate, CN = cellulose nitrate, NY = nylon.

9

Bottle Top Vacuum Filters w Individually packaged, sterile and certified nonpyrogenic w Available in 33 mm and 45 mm neck sizes to fit most glass and plastic media storage bottles w 45 mm neck sizes fit on Corning® plastic storage bottles (see below).

Bottle Top Vacuum Filters Ordering Information Cat. No. Membrane

Volume (mL)

Neck Size (mm)

Pore Size (µm)

Qty/Cs

150 mL Capacity, 42 mm Square Membrane 430624 CA 150 33 0.22 48 430625 CA 150 33 0.45 48 430626 CA 150 45 0.22 48 430627 CA 150 45 0.45 48 431160 PES 150

33 0.22 48

431161 PES 150

45 0.22 48

500 mL Capacity, 63 mm Square Membrane 430049 NY 500

45

0.2 12

430512 CA 500 33 0.45 12 430513 CA 500 45 0.22 12 430514 CA 500 45 0.45 12 430521 CA 500 33 0.22 12 431117 PES 500

33 0.22 12

431118 PES 500

45 0.22 12

1,000 mL Capacity, 79 mm Square Membrane 430015 CA 1,000 45 0.22 12 431174 PES 1,000 45 0.22 12 PES = polyethersulfone, CA = cellulose acetate, CN = cellulose nitrate, NY = nylon.

Corning Glass Fiber Prefilters w For use with vacuum filter systems or bottle top vacuum filters

Corning Glass Fiber Prefilters Ordering Information Cat. No.

10

Shape

Filter Funnel (mL)

Qty/Cs

431410

42 mm Square

150

100

431411

49.5 mm Square

250

100

431412

63 mm Square

500

100

431413

79 mm Square

1000

100

Polystyrene Storage Bottles w Disposable polystyrene bottles for storage of media, buffers and other aqueous solutions w Two styles:

- Low profile, easy grip style has sides that facilitate handling - Traditional style has smooth sides w Plug seal caps (45 mm) provide an airtight seal and help minimize the risk of contamination. w Bottles can be used with Corning® vacuum filter systems (see pages 9-10). w Sterile, certified nonpyrogenic

Corning Easy Grip Style Storage Bottles Ordering Information Cat. No.

Volume (mL)

Neck Size (mm)

Qty/Pk

Qty/Cs

431175

150

45

2 24

430281

250

45

2 24

430282

500

45

2 24

1,000 45

2 24

430518

Costar® Traditional Style Storage Bottles Ordering Information Cat. No.

Volume (mL)

Neck Size (mm)

Qty/Pk

Qty/Cs

8388

125

45

1 24

8390

250

45

1 12

500

45

1 12

1,000 45

1 12

8393 8396

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U l t ra F i l t ra t io n Introduction Corning® Spin-X® UF concentrators are disposable, single use only ultrafiltration devices with polyethersulfone membranes (PES) for the centrifugal concentration and/or purification of biological samples. This guide will help you chose the best Spin-X UF ­con­centrator for your application.

Major Uses for Ultrafiltration Ultrafiltration is a convective process that uses anisotropic semi-permeable membranes to separate macromolecular species and solvents primarily on the basis of size. It is par­ticularly appropriate for the concentration of macromolecules and can also be used to purify molecular species or for solvent exchange (Table 1). Ultra­filtration is a gentle, non-denaturing method that is more efficient and flexible than alternative processes. Solute Concentration Ultrafiltration membranes are used to increase the solute con­centration of a desired biological species. The filtrate is cleared of macromolecules which are significantly larger than the reten­tive membrane pores. Microsolute is removed convectively with the solvent. Solute Desalting or Purification A solution may be purified from salts, non-aqueous solvents and generally from low molecular weight materials. Multiple solvent exchanges will progressively purify macromolecules from conta­minating solutes. Microsolutes are removed most efficiently by adding solvent to the solution being ultrafiltered at a rate equal to the speed of filtration. This is called dia­filtration.

Choosing the Right Concentrator Doesn’t Have to be Complicated Corning offers Spin-X UF concentrators in three sizes. The information below and Tables 2 and 3 will help you find the best ­concentrator for your needs.

1. Corning Spin-X UF 500 for 100 to 500 µL samples Spin-X UF 500 µL centrifugal filter units offer a simple, one step procedure for sample prep­ aration. They can effectively be used in fixed-angle rotors accepting 2.2 mL centrifuge tubes. The vertical membrane design and thin channel filtration chamber minimizes membrane fouling and provides high speed concentrations, even with particle laden solutions.

2. Corning Spin-X UF 6 for 2 to 6 mL samples Spin-X UF 6 mL concentrators have been developed to offer increased volume flexibility and performance. Spin-X UF 6 con­centrators can process up to 6 mL in swing bucket or fixedangle rotors accepting standard 15 mL conical bottom tubes. In a single spin, solutions can be concentrated in excess of 100-fold. Samples are typically concentrated in 10 to 30 minutes with macromolecular recoveries in excess of 95%. The Spin-X UF 6 features twin vertical membranes for unparalleled filtration speeds and 100x plus concentrations. Remaining volume is easy to read off the printed scale on the side of the concentrator and the modified dead stop pocket further simplifies direct pipet recovery of the final concentrate.

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3. Corning® Spin-X® UF 20 for 5 to 20 mL samples Spin-X UF 20 mL centrifugal concentrators have been developed to offer increased volume flexibility and performance. Spin-X UF 20 handles up to 20 mL in swing bucket centrifuges and 14 mL in 25˚ fixed-angle rotors accepting 50 mL centrifuge tubes. Featuring twin vertical membranes for unparalleled filtration speeds, the Spin-X UF 20 can achieve 100x plus concentrations. Remaining volume is easy to read off the printed scale on the side of the concentrator and the modified dead stop pocket further simplifies direct pipet recovery of the final concentrate. Table 1. Typical Ultrafiltration Applications w General

purpose laboratory concentration and desalting of proteins, enzymes, cells, biomolecules, antibodies and immunoglobulins w Removal of labeled amino acids and nucleotides w HPLC sample preparation w Deproteinization of samples w Recovery of biomolecules from cell culture supernatants, lysates

Table 2. Technical Properties of Corning Spin-X UF Concentrators Concentrator 20

Spin-X UF 500

Spin-X UF 6

Spin-X UF

Do not use 500 µL 40°

6 mL 6 mL 25°

20 mL 14 mL 25°

50 mm 11 mm 0.5 cm2